Sorting system

ABSTRACT

An improved system for sorting mail is described, comprising a sorting machine which uses information collected about each mail item, such as address and size or weight, to map its collection bins to a specified sort order. The sorting machine has, instead of a small number of large sort bins, a large number of small bins. In this way, a small number of mailpieces may be allocated to each bin, for example, each bin may be an individual house or person at a business address The information about each mail item is achieved by communicating data to the machine before any mail is processed through it. The data may be derived from sensors which scan the mailpiece during the initial phase of the sorting process in conventional sorting systems, or may be supplied by the producer of the mail. The data is configured and transmitted electronically ahead of the physical mail. As the sorting machine is aware of the number, destination and thickness of each mailpiece, it is possible to allocate a sufficient space in the relevant sort bin for each mailpiece. In this way, mail from several sources may be merged as long as the electronic data is written to the machine in advance. As each mailpiece is uniquely identified it is possible to allocate a unique position in the machine to each mailpiece.

TECHNICAL BACKGROUND TO THE INVENTION

[0001] This application relates to an improved method and apparatus forsorting items, and in particular to an improved method and apparatus forsorting items of mail.

[0002] Sorting machines for organizing papers or documents into apredetermined order, based on some input information, are well known.Such machines are essential in the operation of postal deliveryservices, for example, in which incoming items of mail or ‘mailpieces’,received in no particular order, are sorted and placed in collectingbins according to the address to which they should be delivered.

[0003] Conventional postal sorting machines sort the mailpieces usingthe postal code of the address to which the mailpiece is to bedelivered. Each new mailpiece received at a mail delivery centre isscanned by a visual recognition system in order to retrieve the postalcode information of the delivery address. This information is thenconverted into a machine-readable code which is printed on themailpiece. If the postal code is missing or, for some reason, cannot beread by the visual recognition system, the mailpiece will be passed toan operator who can manually enter the relevant postal code for printingas a machine-readable code. After the mailpieces have been coded theyare sorted into batches corresponding to the delivery area. They arethen sent to the mail delivery centre corresponding to the mailpieceaddress for sorting and delivery.

[0004] To sequence sort mail in the order that it would be delivered bya delivery person, most conventional sorting machines require that asingle mailpiece be sorted more than once in order for it to arrive atthe correct final collecting bin. Such sorting machines are known asmultipass sorting machines.

[0005] In a first passe the machine sorts each mailpiece in a batch ofmail into collecting bins according only to the first digit or digits ofthe mailpiece's machine-readable postal code. The mail then has to becollected from the bins and re-input into the sorting machine for asecond pass, which then sorts the mailpieces by the next digit or digitsof the machine-readable code. Each subsequent pass of the mailpiecesthrough the machine refines the sort until finally they are placed intothe correct collecting bins. Some sorting machines require four passesof the mailpieces for sorting to be completed.

[0006] A simple example of a multipass sorting process is shown inFIG. 1. In this example, the address information of each mailpiece isrepresented by a three digit number in the same way that addresses areusually represented by a postal code.

[0007] The mail is input into the machine in no particular order. Thefirst pass of the machine sorts the mail according to the last digitinto three sort bins. The first bin contains all mailpieces with anaddress that ends with the digit ‘1’, the second sort bin contains allmailpieces with an address that ends with the digit ‘2’ and the thirdsort bin contains all mailpieces with an address that ends with thedigit ‘3’. The order of the mailpieces within the sort bins isillustrated by a table in FIG. 1.

[0008] The mailpieces are then retrieved from the sortbins and re-inputfor a second pass in the exact order in which they were extracted. Inconventional sorting machines, the bottom of each sorting bin is pulledaway to release the mail onto a conveyor below for recollection.

[0009] This means that the first mailpiece to come out of the machinefollowing the first pass is mailpiece ‘123’, then working up throughsort bin 3, mailpieces ‘213’ and ‘333’ followed by the bottom-mostmailpiece in sort bin 2 and so on.

[0010] The extracted mailpieces are then sorted into bins according tothe second digit of the address. As a result, all mailpieces with ‘1’ asthe middle digit of the address are placed in bin 1; all mailpieces with‘2’ as the middle digit of the address are placed in bin 2 and allmailpieces with ‘3’ as the middle digit of the address are placed in bin3. Within each sorting bin the mailpieces are now in order with respectto the last two digits of the address, as illustrated by table b shownin FIG. 1.

[0011] Once again, the mailpieces are removed from the sorting bins fromthe bottom of the leading sorting bin (in this case, bin 3). The firstmailpiece to come out of the machine is mailpiece ‘333’ followed by‘132’, ‘231’, ‘123’, ‘222’ and so on.

[0012] Preserving the order in which they were extracted, the mailpiecesare then re-input into the machine for a third and final pass in whichthey are sorted according to the first digit of the address. As aresult, the mailpieces are now ordered within each sorting bin withrespect to all three digits of the address, as illustrated in table cshown in FIG. 1.

[0013] The mailpieces may then be extracted from the sorting bins in aconvenient order for the mail delivery worker to deliver during hisroutes that is ‘333’ first so that it is at the bottom of the sortedpile, followed by ‘321’, ‘312’, ‘231’, ‘222’, ‘213’, ‘132’, ‘123’ andfinally ‘111’.

[0014] From this example, it can be seen that multipass sorting machinesrequire that between passes the order of the mailpieces is notdisrupted; mailpieces must be re-input into the machine for a subsequentpass in the exact order in which they have been output from thepreceding pass, otherwise the mailpieces will not be correctly sorted.

[0015] Also, to sort a single batch of mailpieces using a multipasssorting machine requires the mail to be input up to four times, and thustakes more time than would be necessary if the mail could be sorted in asingle pass. A known multipass sorting machine is the Siemens SPACSmachine which can input or ‘singulate’ 48,000 mailpieces per hour, but,since the sorting process requires three passes of a mailpiece, caneffectively sort only approximately 15,000 mailpieces per hour.

[0016] Mailpieces sorted in this way pass along the conveyors and guidewheels of a multipass sorting machine more than once and are thereforesubject to increased wear and tear.

[0017] Multipass sorting machines are therefore designed to ‘singulate’mailpieces at faster and faster speeds to compensate for the much lowersorting speed. ‘Singulating’ is the term used to describe the separationof a single mailpiece from a stack of mailpieces to be input into thesorting machine. These ‘faster’ machines tend to be more complex and somore difficult to maintain and adjust. Thus, it is necessary to havetechnically trained operators present to ensure that the machine isrunning optimally.

SUMMARY OF THE INVENTION

[0018] The invention is defined in the appended claims to whichreference should now be made.

[0019] The preferred system allows items of mail or mailpieces to besorted exactly to an order which may be specified in a single pass ofthe sorting machine. Mail can therefore be sorted by the machine quicklyand with less wear and tear than known multipass sorting machines.

[0020] Mail that is not correctly sorted in the single pass can bereinserted to be sorted again, or can be manually placed into thecorrect sorting bin.

[0021] The preferred sorting machine has the ability to merge mailpiecesof different sizes and those which originate from different sources,such as public collection boxes and mailing houses.

[0022] The sorting machine according to the preferred embodiment of thepresent invention has, instead of a small number of large sort bins, alarge number of small bins. In this way, a small number of mailpiecesmay be allocated to each bin, for example, each bin may be an individualhouse or person at a business address. The mailpieces are routed to thebin using prior knowledge. This is achieved by communicating data to themachine before any mailpieces are processed through it. Some of thisdata is derived from machines which scan the mailpiece during theinitial phase of the sorting process in present conventional sortingsystems. Data can also be derived from the mailpiece producer. Theproducer may supply relevant data related to the mail they havegenerated. This data is configured and transmitted electronically aheadof the physical mail. The electronic data may typically includeinformation of destination, addressee, the mailpiece physicaldimensions, mailpiece weight and thickness, This data is then used tomap the sorting bins of the machine in accordance with the mail about tobe processed. As the sorting machine is aware of the number, destinationand thickness of each mailpiece, it is possible to allocate a sufficientspace in the relevant bin for each mailpiece in the machine. In thisway, mail from several sources may be merged as long as the electronicdata is written to the machine in advance. As each mailpiece is uniquelyidentified it is possible to allocate to it a unique position in themachine in advance of its input.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] A preferred embodiment of the invention will now be described inmore detail and with reference to the drawings in which:

[0024]FIG. 1 illustrates the order of mailpieces within sorting bins ateach stage of an example known multipass sorting operation;

[0025]FIG. 2 is a schematic illustration of the preferred sorting systemaccording to an embodiment of the invention;

[0026]FIG. 3 is an illustration of the input means of the preferredsorting machine;

[0027]FIG. 4 is a simplified side view of the sorting machine;

[0028]FIG. 5 is an enlarged view of the sorting bins provided on asorting deck of the sorting machine shown in both ‘sorting’ position and‘output’ position;

[0029]FIG. 6a shows a three dimensional top view of a preferred diverterplate used in the preferred embodiment of the sorting machine;

[0030]FIG. 6b shows a three dimensional bottom view of the preferreddiverter plate shown in FIG. 6a;

[0031]FIG. 7a shows a top view of an array of the diverter blades shownin FIGS. 6a and 6 b as arranged in the preferred embodiment of thesorting machine;

[0032]FIG. 7b shows a longitudinal cross-section through the array ofdiverter blades along line 7-7 in FIG. 7a, when all diverter plates areclosed;

[0033]FIG. 7c shows a longitudinal cross-section through the array ofdiverter blades along line 7-7 in FIG. 7a when the central diverterplate is open;

[0034]FIG. 7d shows the mounting spindle on which the sorting bin guideplates are suspended;

[0035]FIG. 8a shows a top view of the solenoid arrangement fordeflecting the diverter blades of the preferred sorting machine;

[0036]FIG. 8b shows a side view of the solenoid arrangement of FIG. 8a;and

[0037]FIG. 8c shows two views of the front of solenoid arrangement shownin FIGS. 8a and 8 b in a resting and activated position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] The preferred embodiment of the invention is a system comprisinga sorting machine control system and sorting machine which enablesmailpieces to be sorted into a predetermined order in just a single passor working cycle of the machine. Since mailpieces need to be input intothe machine only once, the sorting process is much faster. In addition,the condition of the mail after sorting is likely to be better than thatof known multipass sorting machines as only one pass is needed to sort.The novel design of the collecting bins in conjunction with a wideconveyor transport system, allows mailpieces of a wide range of sizes tobe handled by the sorting machine.

[0039] The preferred embodiment of the single pass sorting machine willnow be described in detail with reference to FIGS. 2 to 8.

[0040]FIG. 2 is a schematic illustration of a preferred system 100embodying the invention. The system is divided into four main sections;the first of these represents the collection and cataloguing of mail atlocal receiving sections and is shown in the top left of the diagramcomprising components 102 to 128; the second section, shown next to thefirst in the top right corner of the diagram and comprising components104 to 136, represents the generation of items of mail by an externalmail producer. The third section, shown below the first two sectionscomprising components 140 to 144, represents the transmission of themail and mail information from the local receiving office and externalmail producer to a local delivery office. The local delivery officeforms the fourth section of the system and comprises components 150 to152.

[0041] The components making up each of these sections will now bedescribed in more detail.

[0042] The top left corner section illustrates the reception andindexing of mail in a typical letter sorting office or local mailreceiving office. Mail 102 is received from posting points in the localarea, taken to the receiving office and input into the local sortingmachine 110. Local sorting machine comprises means 112 for receivingmail, means 114 for scanning the mail address information, means 116 fordetermining the characteristics, such as size and weight, of each pieceof mail, means 118 for printing tag or route information on an item ofmail, and means 120 for receiving items of mail sorted according to thedestination delivery office. In the preferred embodiment, an OCR(Optical Character Recognition) Scanner is used as scanning means 112.‘Tag’ information in this context means a unique identifier for thatparticular item of mails whereas ‘route information’ means an identifierfor the address to which the mail piece is destined.

[0043] Mail 102 received at the input device 112 of the sorting machine110 is caused, during the sorting process, to pass in turn through eachof the different means or parts mentioned above. Each of these parts iscontrolled by a Machine Control system 126 which additionally receivesthe addressing information and characteristic information for each itemof mail sorted.

[0044] Machine Control System 126 is also connected to means 124 formanually entering the address information into the control system ifthis information cannot be extracted through the scanning means 114. Theaddress information and characteristics of each mail item aretransmitted by the control system to Outward Office Computer System 128.

[0045] Once sorting of the mail has been completed at the localreceiving office, the mail is delivered by transport means 142 to thedelivery office illustrated in the bottom-most section of FIG. 2. Also,the address information and characteristics of each mailpiece deliveredto that delivery office are transmitted by Outward Office ComputerSystem 128 via Network 140, to the Computer System 150 of the deliveryoffice.

[0046]FIG. 2 also shows in the top right corner example production ofmail by external mail producers. Customer data 104 is entered into thecomputer system 130 of the mail producer. The computer system 130 isconnected to printing machines 132 which it instructs to produce themail or letter to be sent to customers specified in the customer data104. The printing machines are also instructed to produce addressed andpossibly tag encoded envelopes for each customer letter. The letters andenvelopes are passed to means 134 for combining the letters andcorresponding envelopes to be sent out as mail. The printing machinesand document inserting machine communicate with Outward CustomerCommunication System 136 to pass on mail information about the mailpieces sent out. This mail is then delivered by transport means 144 to apre-designated delivery office which serves the addresses of the mailsent out. The address information and characteristics, such as size andweight, of all mail sent out are maintained by Customer Computer System136, which once the mail has been sent out transmits this information,via Network 140, to the Computer System 150 of the pre-designateddelivery office.

[0047] The delivery office itself comprises a computer system 150connected to Network 140 for receiving mail information and forprogramming sorting machine control system 152 which controls one ormore sorting machines 154 (not shown in FIG. 2) at the delivery officeto sort the mail into the correct order for a mail delivery worker todeliver the mail to the addresses on his route. Route information may beentered onto the delivery office computer system so that the sort ordermay be determined.

[0048] The preferred sorting machine for use with the preferred systemwill next be described with reference to FIGS. 3 to 6.

[0049]FIG. 3 shows a top view of the ‘singulaters’ used to input mailfor sorting into the sorting machine and the bottom deck of the sortingmachine 154. A first ‘singulater’ 210, comprises conveyor belt housing212 and input conveyor belt 214. Conveyor belt housing 212 has an inputend 216 at which mailpieces can be loaded onto input conveyor 214. Aperson loading the mail onto the conveyor may stand at the input end ofthe conveyor or behind the long side of the conveyor housing to placemail for input along the length of the conveyor. Situated at the otherend of the conveyor housing 212, are barrier 218 and feed conveyor 224,mounted on first and second feed conveyor guide wheels 220 and 222.First guide wheel 220 is situated approximately on the central axis ofthe input conveyor 214. The direction of travel of feed conveyor 224 isdisposed perpendicular to input conveyor 214 and is adjacent to, barrier218, disposed between first guide wheel 220 and input conveyor housing212.

[0050] The end of the feed conveyor 224 distant to the input conveyor214 abuts twin feed conveyors 251 and 252 which are disposed adjacentone another and which themselves abut a control portion of main conveyorassembly 255.

[0051] The main conveyor assembly 255 is supported on the bottom orinput deck 250 of the sorting machine 154, and stretches longitudinallyalong its length.

[0052] A second singulater 230, identical to the first 210, lies behindthe first singulater but adjacent to the input deck 250. The secondsingulater similarly comprises conveyor belt 234 supported by conveyorbelt housing 232 with input end 236, barrier 238, and feed conveyor belt244 mounted on first and second conveyor rollers 240 and 242.

[0053] The end of the feed conveyor belt 244 distant to the inputconveyor 234 abuts twin feed conveyors 253 and 254 disposed adjacent oneanother and which together about the end of main conveyor assembly 255.

[0054] The main conveyor assembly 255 is a series of conveyor beltsmounted on guide wheels 256 which acts to draw mail from the singulaterfeed conveyors 251, 252 and 253 and 254 along the input deck to a pairof vertical feed conveyors 210 and 280.

[0055] Referring to FIG. 3, it will be appreciated that mailpieces oncethey have entered the main conveyor assembly are carried leftwards tovertical feed conveyors 270 and 280 at which point the mailpieces arecarried in a direction up and out of the page.

[0056] The preferred sorting machine is provided with two singulatersand two arrays of sorting bins, disposed on either side of the machine,and served independently by one of the two vertical feed conveyors 270or 280. This arrangement allows the sorting machine to be used flexibly,allowing for example, a single singulater and array of sortbins to beallocated to a one sort while the other singulater and array of sortbins are allocated to another sort; alternatively, both singulaters andarrays of sort bins may be allocated to the same sort for fasterprocessing. Possible uses of the machine will be described in moredetail later.

[0057] In order to direct mail from either singulater to either of thevertical conveyors 270 and 280 and thus to either side of the machine,the main conveyor assembly 255 is provided with two sets of readers 262,264 and diverters 266 and 268. The readers 262, 264 scan each mailpiecethat passes through for the machine readable address information or postcode printed on the mailpiece, and notifies the controlling computersystem that the mailpiece has been received and read by that particularreader, at that particular time. The controlling computer system maythen operate the appropriate diverter 266 or 268 to direct the mail tothe allocated side of the machine and the allocated sort bin.

[0058] Reference will now be made to FIG. 4 which shows the preferredembodiment of the sorting machine 154 in a side view.

[0059] It will be seen from FIG. 4 that the singulating apparatus shownin a top view in FIG. 3 comprises the bottom-most layer 250 of thesorting machine. The conveyor belt assembly 255 and singulaters 210 and230 shown in FIG. 3 are not shown in FIG. 4 to avoid complicating thediagram.

[0060] The preferred sorting machine shown in FIG. 4 comprises inputdeck 250 and one or more sorting decks 300 comprising input conveyors302, an output conveyor 304 and an array of collecting or sorting bins306. Only one sorting deck 300 is shown in FIG. 4 for the sake ofsimplicity, but others could be provided either above or below thatshown to provide a larger array of sorting bins.

[0061] Mail is passed to the input conveyor of sorting deck 300 by thevertical conveyor assembly 290. This will be understood to comprisevertical feed conveyors 270 and 280 shown in FIG. 3. Each of theseconveyors comprises a belt 292 borne on rollers 294 and 296, and acts tocarry mail from the input deck 250 to the top sorting deck 300. Verticalconveyor assembly 290 may also contain diverters 298 to divertmailpieces to subsequent sorting decks if these are provided.

[0062] Referring next to FIGS. 5 to 8 the structure of the sorting deckwill be described in more detail.

[0063]FIG. 5 shows an enlarged view of the array of collecting bins 306shown in FIG. 4. It will be seen from this figure that the sorting bins306 comprise a curved plate 308 which hangs suspended from the uppersurface of the sorting deck 300 on which input conveyor 302 is mounted.Input conveyors 302 are borne on rollers 303. The upper surface of thesorting deck will be described in more detail later with reference toFIGS. 6 to 8.

[0064] Mailpieces are transported to input conveyors 302 of the sortdeck by vertical conveyor assembly 290 pass along the conveyor, fromleft to right in FIG. 5, and are deflected into a pre-designated sortbin 306 by the control system of the sorting machine. The mailpiecefalls down the underside of the curved plate 308 or guide in front of ituntil it comes to rest against output conveyor belt 304 which stops itsfall and keeps the mailpiece upright within the sorting bin. Thecurvature of plate 308 means that any subsequent mailpieces deflectedinto the bin may slot neatly behind the mailpiece in front of it. Thishelps to keep the mailpieces in the sorting bin neatly stacked and inthe order in which they entered the bin.

[0065] The curvature of the curved plate or guide 308 causes themailpiece to deform and thus partly absorb the energy in it. The regionof the guide which meets the leading edge of the mailpiece is providedwith a material 309 that acts as a break. The braking action that itprovides reduces the speed with which the mailpiece meets the stationaryoutput conveyor and allows the mailpiece to come to rest in a morecontrolled manner.

[0066] The array of sorting bins 310 shown to the right of FIG. 5 areidentical in structure and shape to the array of sorting bins 306 butare shown in a raised position. The sorting bins may be raised fromtheir rest position by pulling the bottom of each sorting bin guideplate 308 rightwards by means of an actuator connected to pins 312.Raising the sorting bin guide plates 308 allows the mail containedtherein to fall out onto the output conveyor belt 304. The outputconveyor belt carries the mailpieces towards the output end of thesorting machine, shown on the right in FIG. 4, where they may becollected for delivery.

[0067] Although only two arrays of sort bins are shown in FIGS. 4 and 5it will be appreciated that the sorting machine is modular in design andmay comprise one or more arrays of sorting bins depending on thespecified requirements of the machine user. These will need to be givenduring machine installation. Only two arrays are shown in FIG. 4, inmodules 1 and 2, to avoid complicating the diagram; the arrays ofsorting bins in modules 3, 4 and x have been omitted. ‘X’ is intended toindicate an arbitrary module meaning that the sorting machine shown inFIG. 4 may also be more than five modules in length. The number of sortbins per module may also be determined by the requirements of the user,as for the number of modules and the number of sorting decks per module.

[0068] Referring now to FIGS. 6 to 8, the mechanism for diverting amailpiece from the input conveyor 302 to a pre-designated sorting bin306 will next be described.

[0069] A mailpiece is deflected into a sorting bin 306 using diverterblades 320 of the type shown in FIGS. 6a and 6 b.

[0070] Diverter blade 320 comprises a substantially flat plate 322 whichcurves a round at one edge to join back on itself forming a loop. Formedintegral to the loop and extending slightly beyond the edges of theplate is sleeve 340. The sleeve is hollow and receives a spindle ofsmaller diameter 360, not shown in FIGS. 6a or 6 b, by which thediverter blade is caused to rotate. Plate 322 is provided with a cutaway section 330 at the curving edge with a shape that matches theprofile of the leading edge 326, 328 of the diverter blade 322.

[0071] Briefly referring to FIGS. 7a and 7 b it will be seen that thediverter blades are arranged adjacent to one another in rows, one rowbehind another. This arrangement of diverter plates forms the top of thesorting deck over which the mailpieces pass and under which the sortbins are disposed. The mailpieces are driven along the sorting deck bymeans of input conveyors 302 positioned between the diverter blades. Thecut away section of one diverter plate receives the leading edge of thediverter blade plate in the row directly behind it in an interlockingarrangement so that both diverter plates form a horizontal surface formailpieces to slide over. The interlocking arrangement allows thediverter blade to be long, advantageously providing a gentler deflectinggradient to a mailpiece when the blade is raised, while allowing thesort bins to be placed closer together reducing the overall spacerequirements.

[0072] Referring again to FIGS. 6a and 6 b it will be seen that theleading edge of the preferred diverter blade plate 322 is provided witha flat jutting out portion 326, of narrower width than plate 322, whichangles downwards at its end to form a lip or flange 328. Jutting outportion 326 and lip 328 are received in the cut out portion 330 of thepreferred diverter blade and make contact with shoulder 332 and ridge334 respectively. It will be appreciated that other designs of cut outportion and leading edge profile may also be used.

[0073]FIG. 6b shows the underside 324 of the preferred diverter blade320. The underside 324 of the plate has a longitudinal spine 336disposed along its central axis which curves from being narrow where itjoins lip 328 to being thick where it joins the curved sleeve at theother end of the plate. This curvature forms a gently sloping deflectingsurface 336 which acts to deflect the mailpiece from its horizontal pathalong the top of the diverter blade in the preceding row downwards intoa sorting bin when the diverter blade is raised. Ridge 334 can be seento be the side of spine 336 opposite to the deflecting surface 338 wherethe spine passes under the cut out 330 in the plate 322.

[0074] Referring now to FIGS. 7a and 7 b, the arrangement and operationof the diverter blade assembly will next be described.

[0075] The diverter blade assembly 350 comprises a number of shafts orspindles 360 which are supported on the frame of the sorting deck bypivots 362. Disposed on the spindle 360 are a number of adjacentdiverter blade 320 and roller 364 pairs. In the preferred embodimentthere are three diverter blades with rollers 264 in between and longrollers 366 at each end.

[0076] The spindle passes through the sleeve 340 of the diverter bladesand is provided with flats which engage in the diverter blade sleeve sothat as the spindle turns the diverter blade is caused to rotate withthe spindle. Neither the flats on the spindle or the diverter platesleeve are visible in the drawings. Rollers 364 and 366 on the otherhand are freely mounted on the spindle and rotate as an item of mailpasses over them. Input conveyor belts 302 pass over the rows of thediverter assembly 350 in a direction towards the leading edge of thediverter is blades at positions above rollers 364,366, that is from thebottom to the top of the assembly shown in FIG. 7a. Mail is carried inbetween the input conveyor belts 302 and the substantially flat surfaceprovided by the rollers 364 and 366 and closed diverter blades 320. Aside view of the arrangement of closed diverter blades is shown in FIG.7b.

[0077]FIG. 7b is a cross section through the diverter assembly shown inFIG. 7a along line 7-7 when all of the diverter plates are closed. Theinterlocking configuration of the leading edge profile 326 of thediverter blades and the cut out or recess 330 is clearly shown. On thescale shown in this figure, the tops 322 of each diverter blade form asubstantially flat surface along which mailpieces may move. In thepreferred embodiment of the diverter assembly the position of thespindles 360 and the orientation of the diverter blades 320 is such tointroduce a slight convex curvature into the surface. This curvature issufficient to ensure that the tension of the belt running across the topof the surface rollers 364 and the drive capability of the beltingsystem is sufficient without the need for additional pressure to beapplied between the belt and the rollers thus enabling positive drivebetween belt and mailpiece. In the preferred embodiment the radius ofcurvature of the diverter assembly is about 12-16 m over an arc lengthof about 1 m.

[0078] The curved plates 308 which form the sorting bins are suspendedfrom mounting spindles 390 adjacent the spindle on which the diverterblades and rollers are mounted to form an array of sorting bins 306 asshown in FIG. 5. The curved plates 308 or mounting spindles are nothowever shown in FIGS. 7b or 7 c.

[0079]FIG. 7d shows a simple illustration of the mounting spindle 390 onwhich the curved guide plates 308 of the sort bins are suspended. One ofthese spindles 390 is mounted on the frame of the sorting deck adjacentto each diverter and roller assembly. The curved plate 308 of thesorting bin hangs vertically down from this spindle to form one edge ofa sort bin.

[0080] If a mailpiece is to be directed to a sorting bin, the controlsystem of the sorting machine causes the appropriate spindle 360 torotate, causing a row of diverter blades 320 to be opened and adopt theraised position of the central diverter blade showing in FIG. 7c.

[0081] A mailpiece driven to the right along the top surface of thediverter assembly by the input conveyor 302 encounters the deflectingsurface 338 on the underside of the raised diverter blade. Thedeflecting surface is so shaped to cause the mailpiece to deform anddeflect from linear travel into the sort bin below. Once the mailpiecehas been deflected into the sort bin the diverter blade is rotated intothe closed position.

[0082] The mechanism which causes the spindle 360 to rotate and open thediverter blades is shown in FIGS. 8a, 8 b and 8 c.

[0083]FIG. 8a shows the left hand side of the diverter assembly 350 ofFIG. 2a in an enlarged view.

[0084] Spindle or shaft 360 is attached to a rotary solenoid 380 via acoupling 370. Solenoid 380 is secured in place on the frame of thesorting machine by pins 381. The coupling is shaped to enable the shaftof the roller diverter assembly and the shaft 382 of the rotary solenoidto be coupled by simply inserting each shaft axially within coupling 370as shown in FIG. 8b which is side view of the mechanism shown in FIG.8a. This is achieved by incorporating flats on each shaft in therequired position to enable transmission of torque whilst at the sametime maintaining the relative position of one assembly to the other. Theopening in the coupling 370 is shaped to accept the flats on the shaftof the roller diverter assembly and the shaft of the rotary solenoid.The coupling is so designed to act as both a means of connecting theroller diverter assembly to the rotary solenoid and as means of reactingthe load created by the inertia induced by the operation of the solenoidsee FIG. 8b. The need to support this load becomes more significant inthe event of a malfunction at the point of diversion where a mailpiecebecomes jammed at the diverter blade. In this event much larger forcesneed to be catered for as the mailpiece following the jammed piece willbe driven into it with the full power of the level transport system. Amethod of detecting such an event is built into the control system.However, in view of the speed of the machine and the inertia of thetransport system it is not possible to stop the machine instantaneouslyto avoid more than one mailpiece in a jam. A torque arm 372 is anintegral part of the coupling moulding which rotates when the rotarysolenoid is initiated. At the point where the solenoid comes to rest thearm comes into contact with a rigid pin 384 thus reacting the load. Thisis shown in the two halves of FIG. 8c; in the left half the solenoid isnot activated and the spindle is undeflected. Activating the solenoid380 causes the solenoid shaft 382, coupling 370 and spindle 360 torotate clockwise to the position shown in the right hand half of thefigure. The angle shown here is about 20°.

[0085] The operation of the sorting machine according to the preferredembodiment of the present invention will next be described.

[0086] A item of mail or mailpiece for delivery is received by the localsorting machine 110 of a mail processing centre and is scanned usingknown techniques and apparatus, such as OCR Scanner 114, and mailcharacteristic sensors 116 to determine the address to which themailpiece should be delivered and physical information about themailpiece such as size and weight. In particular the thickness of themailpiece is determined. The address and other information includingsize information is obtained from scanner 114 and sensor 116 by machinecontrol system 126 and input into computer. system 128 where it is givena unique reference number for identification. The reference number isprinted onto the mailpiece as a machine-readable code using printer 118.The information describing the mailpiece is then transmitted e.g. vianetwork connection 140 to the computer system of the delivery centre 150and stored in memory. The mailpiece is then sent to the mail deliverycentre dealing with the mail delivery for the area specified on theaddress of the mailpiece.

[0087] Mailpieces from mailing houses and companies that bulk mail-shotare not usually ‘posted’ in the same way as ordinary mail and so are notnecessarily received at a mail receiving centre where the mailpiecedetails may be input into the system. Instead they are sent directly toeach mail delivery centre for delivery to each address in the centre'scatchment area. Such mailpieces pose a problem in conventional maildelivery systems since the amount of mail cannot be predicted in advancemaking it necessary to sort bulk mail and individually directed mailseparately.

[0088] The preferred system provides a solution to this problem howeverby providing means to enter data about the mailing house's intendeddelivery into the system before any mail is received at a deliverycentre. In the system illustrated in FIG. 2, customer data 104 is firstentered into the bulk mail producer's computer system 130. This systemthen controls the printing of mail to be sent out using printing machine132 and document inserted 134, and transmits data about the mail such asaddress, and size and weight of the mailpiece to the bulk mailproducer's outward computer system 136. This system then transmits themail data to the destination delivery office computer system 150 acrossnetwork 140. The mail is carried to the destination delivery office byconventional means 144.

[0089] Thus the delivery office control system 150 knows in advance ofsorting the mail exactly what mail it is to receive from local receivingoffices and from bulk mail producers and can instruct the sortingmachine control system 152 to operate the sorting machine in the mostefficient way. This allows both individually addressed mail and bulkmail to be integrated and sorted in a single operation of the machine.

[0090] Once an entire batch of mailpieces has been read into the system,the sorting control system 152 calculates the order in which themailpieces should be arranged according to predetermined routeinformation entered by a user of the system and the address informationheld in memory for each mailpiece. The route information allows a userto specify the exact order into which mailpieces should be sorted. Thismeans that the order can be made to reflect the route walked byindividual postal delivery workers.

[0091] The sorting control system 152 then uses the width and thicknessinformation collected for each mailpiece and the addresses of receivedmail to allocate sorting bins 306 to accommodate the specified sortingorder. Unlike conventional sorting machines, in which each sorting binis used consistently to receive mailpieces with a predetermined postalcode or portion of postal code, the sorting bins of the preferredsorting machine are allocated in response to the route informationentered by the user and the size information for each mailpiece. Binsneed not be allocated to addresses in the route, for which no mailpiecesare destined. Similarly, if there is a large amount of mail for aparticular address, more than one sorting bin may be allocated toaccommodate the mail.

[0092] Once the delivery walk order is established, the sorting controlsystem 324 calculates for each position in the delivery walk order, howmany mailpieces will be received, and how many sorting bins need to beallocated to accommodate those mailpieces. The result will depend on thethickness of the mailpieces. The mailpieces deemed to fit in the firstsorting bin are then allocated to the appropriate bin. Next, the controlunit performs a similar calculation for the next position in the walkorder. This process continues until all of the mailpieces have beenmapped to a destination sorting bin.

[0093] The mailpieces are then manually input onto input conveyor 214,and input conveyor 234, to form a stack of mail. The stacks ofmailpieces will comprise mail of all different sizes, weights anddimensions, although preferably is of C5 size or smaller. C5 is themaximum size that can typically be accommodated by conventional inputsingulaters. Mail of size larger than C5 may be sorted by the preferredsystem but cannot be input into the machine while the singulaters areprocessing mail of smaller sizes. Mailpieces are input until theconveyor belts are full or there are no more mailpieces to input. Theinput conveyor belts are then turned on and begin to carry the mail fromthe conveyor input end 216 and 236 to the ends at which the feedconveyor belt 224 and 244 are situated. A first mailpiece arriving atthe feed conveyor belt 224 of singulater 210 will be pushed against thebarrier 218 and the feed conveyor belt 224 by the action of the inputconveyor belt 214 and the mailpieces in the stack behind it. Feedconveyor belt 222, and all the conveyors in the sorting machineaccording to the preferred embodiment of the invention are provided witha surface that has a high coefficient of friction for ‘gripping’ thesurface of a mailpiece. Feed conveyor belts 224 and 244 are additionallyprovided with small holes. A vacuum pump is used in conjunction withthese conveyors to provide a suction which holds the mail to theconveyor. Feed conveyor belt 224 is caused to rotate by rollers 220 and224 in a direction away from the input conveyor 214 and towards theinput deck 250 of the sorting machine. A mailpiece pushed against thesurface of the feed conveyor 224, is pulled off the stack of mailpiecesby the action of the conveyor belt motion and the suction provided bythe vacuum pump, and is input into twin feed conveyors 251 and 252 whichsupport the mailpiece and direct it to conveyor assembly 255 of theinput deck 250. This process is called ‘singulating’.

[0094] The conveyor assembly 255 in conjunction with guide rollers 256carry the mailpiece from the feed conveyor belt 222 to the vertical feedconveyors 270 and 280. The mailpiece is held vertically by the conveyorassembly 255 while it is being conveyed.

[0095] Mailpieces are also singulated at the second singulater 230 andinput into the conveyor assembly 255 by feed conveyor belt 244. Firstand second singulaters 210 and 230 may operate in tandem with each otherto interlace the mailpieces received from the two feed conveyors 224 and244 into a single stream. For this reason it is preferred that mail ofsizes larger than C5 are not input at the same time as smaller mail asthe larger sizes are difficult to interlace with the smaller mailpiecesin an efficient way and because the force required to singulate largermail places greater strain on the singulater feed conveyors. Mail ofsizes larger than C5 can be sorted with the preferred sorting machineand can be merged in with mail of smaller sizes, but it is preferredthat the larger mail is input in a separate process. In the preferredembodiment, a dedicated singulater 314 is provided for this.

[0096] Singulater 314 is located adjacent the vertical conveyors 270 and280. Such a position reduces the path that the larger mail pieces haveto travel, which is advantageous because of their greater size and thecorresponding greater force that is required to transport them. The mailthat is input to the singulater, and from their to the verticalconveyors, is input in a horizontal fashion unlike the mail from thefirst and second singulater which is input standing on edge and whichtherefore receives a 90° twist before passing to the vertical conveyor.The shorter distance of travel and the fact that the mail does notrequiring much directing or manipulating before it passes to thevertical conveyor means that the wear and tear on the larger mail itemsis greatly reduced.

[0097] Conveyor 314 can singulate items of mail of at least C4 sizewhich are then sorted and merged with the other smaller items from thefirst and second feed conveyors. This means that promotional materialfrom companies using the mail service to advertise can be easily mergedwith regular mail.

[0098] Each mailpiece passing through conveyor assembly 255 is read byone of the two readers or scanners 262 or 264. First scanner 262receives mail from singulater 210; second scanner 264 receives mail fromsingulater 230. First scanner 262 reads the machine readable codeprinted on the mailpiece at the local receiving office or the bulk mailproducer and informs the machine control system 152 of the mailpiece'slocation within the sorting machine. Like most sorting machines theposition of the mailpiece within the machine is tracked by an internalclock. Once the machine control system knows where a mailpiece is it mayoperate diverters 266 or 268 to direct the mail to the correct side ofthe machine, and then operate the required diverter plate to direct themail into the designation sorting bin at the right time by monitoringhow long has passed since the mailpiece was read in. Known sortingmachines provide correction methods to ensure that the sorting machine'sinternal clock is in synchronisation with the expected position of themailpiece.

[0099] The arrays of sorting bins in the preferred machine are disposedon the two sides of the machine. Each side is served by a vertical feedconveyor belt, either 270 or 280, and may be allocated to the same ordifferent sorts. Diverters 266 and 268 divert the mail received fromsingulaters 210 and 230 respectively to the appropriate side of themachine.

[0100] Once a mailpiece has been directed to the appropriate verticalconveyor belt by the machine control system it is carried up onto thesorting deck 300 that contains the destination sorting bin for themailpiece. The mailpiece may be carried to the top most sorting deck, ordeflected to lower sorting decks by diverters 298 controlled by machinecontrol system 152. The mailpiece travels along the sorting deck betweendiverter blade assembly 350 and input conveyor 302 until the machinecontrol system determines that it has reached the destination sortingbin. The control system activates the solenoid 380 to rotate the spindle360 and diverter plates 320 just behind the sort bin.

[0101] The mailpiece, travelling along the conveyor on a substantiallyflat aspect with its short edge first, in the case of mail smaller thanC5, or with its long side or spine presented first, in the case of mailgreater than C5, makes contact with the diverter plate and is directedinto the destination sorting bin by means of the sorting bin guide plate3087.

[0102] The control unit then issues a control signal to the solenoid 380causing the spindle and diverter blades to rotate back to its originalposition allowing the following mailpieces to flow past unobstructed.This may be achieved by biasing the spindle with a spring to remainclosed.

[0103] Once all of the mailpieces in a sorting batch have been directedto the correct destination sorting bins, the control unit may issue asignal to raise the sorting bin guide plates 308, to deposit the sortedmailpieces in the sorted order onto the output conveyor belt 304. Thesorted mailpieces can then be output from the machine ready to bedelivered. This represents a considerable advantage over conventionalsorting machines in which sorted mailpieces are retrieved from thesorting bins by hand.

[0104] The operation of the sorting apparatus has been described withreference to just one particular way of allocating the sorting bins.However, other allocation methods are equally possible as will bedescribed next.

[0105] In the simplest mode of operation the control unit allocates eachsorting bin to an individual position or location in the sequence, thisbeing an individual address on the postal delivery worker's route forexample. The sorting bins are allocated in the order that the postaldelivery worker encounters the addresses on his route, so that themailpieces are output from the sorting apparatus after just a singlepass in the order in which they are to be delivered. This mode ofoperation has the drawback that those addresses for which there is nomail have a sorting bin allocated to them. Thus, more sorting bins arerequired for the sort than will be actually used.

[0106] In an improved mode of operation the control unit processes theaddress information for all the items in a sort and only allocates asorting bin to those addresses which are to receive mail and leaves outthose that are not to receive mail. In this way the number of sortingbins that are required to receive the sorted items may be reduced fromthat described above.

[0107] In a further improvement to the mode of operation the controlunit uses the data describing the size of each mailpiece in combinationwith the address information to allocate a sufficient number of sortingbins to each position in the sequence, i.e. address, to receive thesorted mailpieces. Thus, there is no danger of a sorting bin becomingfull and unable to hold any more mailpieces, as the control unitallocates as many sorting bins as are required before the sortcommences.

[0108] In another possible of operation of the sorting machine, asdescribed above, the control unit may make use of the size informationand the address information to fit the mailpieces into the minimumnumber of sorting bins. The control unit calculates the order into whichthe mailpieces are to be sorted and then allocates as many mailpieces toeach sorting bin as will fit, preserving the order of the mailpiecesacross the sorting bins. The sorting bins in this mode of operation arenot assigned to a particular position in the sequence and are used toreceive as many consecutive mailpieces in the order as will fit.Mailpieces for a number of adjacent addresses may be allocated to thesame sorting bin. The viability of this mode of operation is howeverdependent on the order in which the mail is input into the sortingmachine as it is difficult to organise the mailpieces within a sort bin.That is, mailpieces allocated to the same sort bin will be received atthat mail bin in the order in which they were input into the machine. Inorder to use this mode of operation fully, the input order of themailpieces must be scanned before the sort bins are allocated. Sort binscan then be allocated most efficiently.

[0109] The operation of the machine as described above provides areliable and flexible way of sorting mailpieces. The exact order of thesort can be specified, in contrast to conventional sorting machineswhich sort by postcode only. Furthermore, mailpieces from any source,including mailing houses, can be integrated into the sort, providingdata about the mailpieces is received and input into the system prior tothe sort being carried out.

[0110] The preferred system also allows rejected mailpieces, that isthose which for some reason, are not successfully deposited into asorting bin to be output from the system and re-input for sorting. Thecontrol unit ‘knows’ which sorting bin the mailpiece is intended for inadvance so that the order in which the mailpieces are received isentirely irrelevant.

[0111] Mailpieces that are rejected a number of times may also bemanually inserted into the correct sorting bin in the preferred system.The preferred system makes this possible by providing indicator lightswhich correspond to each bin. In order to determine the intendeddestination sorting bin for a rejected mailpiece, a machine operatorenters the reference number of the mailpiece into the computer system150 and in response the sorting control unit 152 lights the indicatorlight corresponding to the intended destination sorting bin so that themachine operator may insert the mailpiece by hand.

[0112] The design of the sorting bins and the upper conveyor 302 andguide roller arrangement, which allow mailpieces to be conveyedhorizontally means that the sorting machine can manage mailpieces with awide range of sizes and weights. In particular the machine is able tohandle C4 size mail and can easily merge C4 and C5 size mail in onepass.

[0113] As described earlier, the sorting machine according to thepreferred embodiment has two sides of collecting bins and twosingulaters for inputting mail. This allows the sorting machine to beoperated in up to four modes; dual singulaters operating separately toproduce two streams of mail, each stream of mail going to each side ofthe machine and comprising mail from only one singulater, dualsingulaters operating together to produce only one stream of mail, thatstream flowing to both sides of the machine, one singulater acting aloneto produce two streams of mail, one for each side of the machine, andone singulater operating alone to produce just one stream of mail whichflows to both sides of the machine.

[0114] Dual singulaters in dual stream mode allows the machine to run atfull capacity. Infeed conveyors 214 and 234 are loaded with mail andfeed each singulater. Each stream of mail from each singulater isdirected to one side of the machine, enabling the machine to run as twomachines that could handle smaller batches of mail for smaller delivery‘walks’. This facility also allows a considerable amount of machineredundancy due to breakdowns as if, for example, a singulater were tofail the machine may continue processing mail with one stream only. Inthis mode the singulaters necessarily run at a faster rate than whendual singulaters are used in a single stream mode.

[0115] Dual singulaters in single stream mode enables mail to flow toboth sides of the machine. In this mode the singulaters will run at aslower rate.

[0116] A single singulater in dual stream mode processes mail using onesingulater to direct mail to both sides of the machine and may be usedif one of the singulaters is to fail. In this mode, the singulater willrun at the higher speed.

[0117] Finally, a single singulater running a single stream processesmail using one singulater to direct mail to one side of the machine.

What is claimed is:
 1. An apparatus for sorting a plurality ofsubstantially flat items for delivery to a plurality of recipients, theapparatus comprising: means for receiving items to be sorted, adestination recipient address being associated with each item; aplurality of sorting bins into which items to be sorted are to bedeposited; guide means, coupled to the means for receiving items and thesorting bins, for directing received items to the plurality of sortingbins; means for inputting data relating to the plurality of items, thedata including at least each destination recipient address; means forinputting data defining a pre-determined sequence of candidate recipientaddresses to which the items will ultimately be delivered; a controlunit for receiving the data relating to the plurality of the items andthe data defining the pre-determined sequence of recipient addresses,for allocating one or more sorting bins to recipient addresses in thesequence in dependence on the data relating to the items, the number ofsorting bins that are allocated to a recipient address being sufficientto accommodate all items that are associated with that destinationrecipient address, and for controlling the guide means to direct theitems to the one or more sorting bins so allocated, and wherein thecontrol unit only operates the guide means to direct the received itemsto the respective sorting bins once it has received the data for theentire plurality of items to be sorted and can allocate sufficientsorting bins appropriately.
 2. An apparatus according to claim 1 whereinthe control unit allocates the sorting bins such that only thosecandidate recipient addresses to which items are to be delivered areallocated one or more sorting bins.
 3. An apparatus according to claim 1wherein the control unit allocates the sorting bins such that candidaterecipient addresses that are adjacent in the sequence are allocatedadjacent sorting bins.
 4. An apparatus according to claim 1 in which thedata relating to the plurality of items includes data describing thedimensions of each item, and wherein the control unit uses this data toallocate one or more sorting bins to a recipient address such that allitems of mail to be delivered to that recipient address can be depositedin the one or more sorting bins so allocated.
 5. An apparatus accordingto claim 1 wherein the means for inputting data relating to the itemshas a terminal at a site remote from the means for receiving the itemsto be sorted, the guide means and the sorting bins; the terminal beingconnected by a network to the control means, such that if the items tobe sorted are initially received at the remote site, the data relatingto the items can be collected and transmitted to the control unit beforethe items themselves are delivered to the means for receiving items forsorting into the sorting bins.
 6. An apparatus according to claim 1 inwhich the items to be sorted are items of mail, and in which the datadefining the sequence in which the items to be sorted comprises theorder in which a mail deliverer completes his route.
 7. An apparatus forsorting according to claim 1 in which each sorting bin further comprisesindication means controlled by the control unit, wherein entering datapertaining to an item to be sorted into the means for inputting datacauses the control unit to activate the indication means for theallocated sorting bin allowing an operator to manually place the iteminto the sorting bin.
 8. A method of sorting a plurality ofsubstantially flat items for delivery to a plurality of recipients, themethod comprising: providing a plurality of sorting bins into whichitems to be sorted are to be deposited; receiving items to be sorted, adestination recipient address being associated with each item; receivingdata relating to the plurality of items, the data including at leasteach destination recipient address; receiving data defining apre-determined sequence of candidate recipient addresses to which theitems will ultimately be delivered; allocating, once all of the datarelating to the plurality of items to be sorted has been received, oneor more sorting bins to recipient addresses in the sequence independence on the data relating to the plurality of the items, thenumber of sorting bins that are allocated to a recipient address beingsufficient to accommodate all items that are associated with thatdestination recipient address; directing, once the sorting bins havebeen allocated to the recipient addresses, the items to the one or moresorting bins allocated to the recipient address corresponding to thedestination recipient address of the item.
 9. A method according toclaim 8 wherein only those candidate recipient addresses to which itemsare to be delivered are allocated one or more sorting bins.
 10. A methodaccording to claim 8 sorting bins are allocated such that candidaterecipient addresses that are adjacent in the sequence are allocatedadjacent sorting bins.
 11. A method according to claim 8 comprising:receiving the items to be sorted at a site remote to the sorting bins;collecting data relating to the items at the remote site, the dataincluding at least recipient address information; and transmitting thedata from the remote site to the site at which the sorting bins arelocated, before the items to be sorted are delivered to that site sothat the data can be used to allocate the sorting bins in advance.
 12. Amethod according to claim 8 in which the data relating to the pluralityof items includes data describing the dimensions of each item, andwherein one or more sorting bins are allocated to a recipient addresssuch that all items of mail to be delivered to that recipient addresscan be deposited in the one or more sorting bins so allocated.
 13. Amethod according to claim 8 in which the items to be sorted are items ofmail, and in which the data defining the sequence in which the items tobe sorted comprises the order in which a mail deliverer completes hisroute.
 14. An apparatus for sorting items of mail comprising; firstinput means for receiving items of mail; a plurality of sorting binsinto which items to be sorted are to be deposited; first guide means forcarrying items of mail to the plurality of sorting bins; second guidemeans for carrying items of mail from said first input means to saidfirst guide means; a second input conveyor for receiving items of mailthat are larger in size than those received by the first input means,said second input conveyor being coupled directly to the first guidemeans such that the mail that is larger in size follows a shorter pathto the sorting bins than the mail input received by the first inputmeans.
 15. The apparatus of claim 14 wherein the sorting bins arearranged above the first and second input means and said second guidemeans is a substantially vertical conveyor belt.
 16. The apparatus ofclaim 14 wherein the second input means is a conveyor belt capable ofreceiving items of mail that are at least C4 or equivalent in size. 17.The apparatus of claim 14 wherein the second input means is a singulatercapable of singulating items of mail that are at least C4 or equivalentin size.
 18. An apparatus for sorting items comprising: a plurality ofcollection bins, each having an opening which may receive an item ofmail, arranged in one or more rows; a diverter blade connected to eachcollection bin, and having a closed position in which it covers theopening to the collection bin to prevent an item of mail from entering;means for supporting items of mail flowing across the top of thediverter blades of each collection bin in a row; and a control unit forcontrolling a diverter blade to direct an item of mail from the items ofmailing flowing across the top of the diverter blades into apre-designated collection bin; wherein each collection bin is providedwith a gently curved guide plate which slopes from being substantiallyhorizontal at the opening of the collection bin to being near verticalat the base of the collection bin.
 19. The apparatus of claim 18 inwhich a region of the curved guide plate which comes into contact with asorted, item as the item enters the collection bin is provided withmeans to slow the item's descent into the collection bin.
 20. Theapparatus of claim 19 in which the means to slow an item's descent is abraking material disposed on the surface of the curved guide plate. 21.The apparatus of claim 18 in which the collection bins are formed by thespace between two adjacent curved guide plates.
 22. The apparatus ofclaim 21 further comprising an output conveyor for carrying sorted itemsaway from the collection bins, the output conveyor having an uppersurface; wherein the output conveyor is positioned below the curvedguide plates of the collection bins such that an item of mail directedinto the collection bin comes to rest between the curved guide platesand against the upper surface of the output conveyor.
 23. The apparatusof claim 22 comprising means for raising the curved guide plates of allof the collection bins such that the items of mail in the collectionbins are output onto the upper surface of the output conveyor in theorder into which they had been sorted.
 24. Apparatus for deflecting anitem of mail into a collection bin comprising: a plurality of collectionbins, each having an opening which may receive an item of mail, arrangedin one or more rows; a diverter blade connected to each collection bin,and having a closed position in which it covers the opening to thecollection bin to prevent an item of mail from entering; means forsupporting items of mail flowing across the top of the diverter bladesof each collection bin in a row; and a control unit for controlling adiverter blade to direct an item of mail from the flow into apre-designated collection bin; wherein the diverter blade comprises asubstantially flat plate having a cut out section into which a portionof an adjacent diverter plate may be received, such that the length ofthe diverter plates may be longer than the separation between collectingbins.
 25. The apparatus of claim 24 wherein the diverter blade isconnected to the collection bin at a pivot, the cut out section beingdisposed at the edge of the flat plate of the diverter blade closest tothe pivot and receiving the leading edge of the converter blade of thecollection bin behind it in the row.
 26. The apparatus of claim 25wherein the leading edge of the diverter blade is provided with aprotruding section of narrower width than the flat plate, the protrudingsection angling down near its tip to form a flange which interlocks withthe cut out section of the diverter blade forward of it in the row ofcollection bins when the diverter blade is in the closed position. 27.The apparatus of claim 24 wherein the diverter blades corresponding toeach collection bin are mounted on a rotatable axle such that rotationof the axle causes the diverter blade to rotate, the axle beingcontrolled by the control means to rotate and cause the diverter todirect an item of mail from the flow of items of mail into a collectionbin; and wherein the means for supporting items of mail flowing acrossthe top of the diverter blades is a plurality of rollers mounted on theaxles such that they is may rotate freely and independently of the axle.28. An apparatus for transporting mail comprising: a number of surfacerollers forming a surface across which the mail is transported; aconveyor belt positioned above the surface rollers such that mail heldbetween the conveyor and the rollers is transported along the surfaceformed by the rollers; wherein the surface rollers are arranged to forma convex surface whereby tension is created in the conveyor belt toensure that mail is kept substantially in contact with the convexsurface.
 29. The apparatus of claim 28 further comprising: a controlunit; a plurality of collecting bins disposed under the surface formedby the rollers; and a diverter blade connected to each of the collectingbins underneath and disposed in between the rollers on the surface, thediverter blade having a first position substantially planar with thesurface and a second position above the surface where it intercepts themail being transported along the surface to direct it into thecollecting bin to which the diverted blade is attached; wherein thecontrol unit may control the diverter blades to direct mail topre-designated collecting bins.
 30. An apparatus for sorting itemscomprising: first and second means for inputting items to be sorted;separate first and second arrays of sorting bins for receiving the itemsin the sort; guide means for directing the items to be sorted to apredesignated sort bin in one of the first or second arrays of sortbins; and control means for operating the guide means; wherein thecontrol means instructs the guide means to direct items such that itemsreceived at either of the first or second input means may be directed toa sort bin in either of the first or second array of sorting bins. 31.An apparatus for sorting substantially flat items, comprising: inputmeans for receiving items to be sorted; a plurality of moveable dividerplates, the space between two moveable divider plates forming a sortingbin for receiving the items following sorting; conveyor means to directthe items from the input means to a pre-designated sort bin; controlmeans to operate the conveyor means such that the items are directed toa pre-designated sorting bin and are sorted into a pre-designated orderacross the sorting bins; and an output conveyor disposed underneath theplurality of sorting bins to receive sorted items; wherein when sortinghas been completed across the sorting bins, the moveable divider platesare raised together causing the items within the sorting bin to fallonto the output conveyor belt such that the order into which they hadbeen sorted is retained.
 32. The apparatus of claim 31 in which themoveable divider plates are fixed to an upper pivot near such that whenthey are raised they rotate around the pivot.
 33. The apparatus of claim31 comprising guide means proximate the entrance to a sorting bin whichangles the items within the sorting bin such that the substantially flatsurface of the item is non-horizontal with respect to the outputconveyor belt.
 34. The apparatus of claim 31 wherein the moveabledivider plates are curved such that an item falling down the curvedsurface of a divider plate is angled to adopt an orientation in whichthe substantially flat surface of the item is non-horizontal to theoutput conveyor belt.
 35. The apparatus of claim 31 wherein the moveabledivider plates are positioned such that the bottom item within thesorting bin comes to rest on the upper surface of the output conveyorbelt.
 36. A method of sorting substantially flat items, comprising;providing a sorting apparatus comprising input means for receiving itemsto be sorted; a plurality of moveable divider plates, the space betweentwo moveable divider plates forming a sorting bin for receiving theitems following sorting; conveyor means to direct the items from theinput means to a pre-designated sort bin; control means to operate theconveyor means such that the items are directed to a pre-designatedsorting bin and are sorted into a pre-designated order across thesorting bins; and an output conveyor disposed underneath the pluralityof sorting bins to receive sorted items; inputting items to be sortedinto the input means; operating the apparatus to sort the items intopre-designated sorting bins; and raising the moveable divider platestogether, when sorting has been completed, causing the items within thesorting bin to fall out onto the output conveyor belt such that theorder into which they had been sorted is retained.
 37. The method ofclaim 36 in which the moveable divider plates are fixed to a pivot nearto their top such that when they are raised they rotate around thepivot.
 38. The method of claim 36 wherein the sorting apparatuscomprises guide means proximate the entrance to a sorting bin whichangles the items within the sorting bin such that the substantially flatsurface of the item is non-horizontal with respect to the outputconveyor belt.
 39. The method of claim 36 wherein the moveable dividerplates are curved such that an item falling down the curved surface of adivider plate is angled to adopt an orientation in which thesubstantially flat surface of the item is non-horizontal to the outputconveyor belt.
 40. The method of claim 36 wherein the moveable dividerplates are positioned such that the bottom item within the sorting bincomes to rest on the upper surface of the output conveyor belt.